Might be firewall issues, depending on the type of traceroute tool. Some
use udp some icmp.

UDP

Do you allow UDP in the firewall rules for tunx, specifically with the
long delays seen above?

To me it is not that obvious what's going on, you could use a tool like
tcpdump on SuSE and Ethereal on the Windoze box, run it on all
interfaces which you think traffic passes through. You will quickly see
where you get stuck.

Please let us know the results.

Unfortunately the Windoze box is 1500 km away, the Capetown box is 40km,
and while I can connect remotely,

Ok, you could at least try at the capetown box, see if your packets
enter the tun interface and if a corresponding UDP